03 - Computree

Spatial resolution & method name used for deriving DTM and DSM (Computree)

Hello guys, How can i get information relating to spatial resolution of the DTM and DSM derived from Computree. Similarly, what is the method name used to derive the DTM and DSM using Computree. I am required to put the method name and spatial resolution in the figure caption.

In the ONF plugin, the step are : ONF_StepClassifyGround (classification of ground points in TLS) and ONF_StepComputeDTM02 (interpolation).

ONF_StepClassifyGround works as follow:- Compute a Zmin grid at specified resolution- Filtering by point density in a slice of specified thickness from ZMin- Filtering by neighborhood consistency (slope test between considered cell and neighbors cells)

ONF_StepComputeDTM02 compute a Delaunay triangulation on not filtered Zmin cells, and interpolate missing ones by a pondered mean (pondered by distance of neighbors in the triangulation). So a method close to a “natural neighbor interpolation”, using distances instead of triangles areas.

The DSM creation is just a ZMax computation by ONF_StepComputeDSMOnly step.

If you use the method provided by plugin SimpleTree, please ask to Jan Hackenberg directly.

The easiest solution is to:- Select “Item information” action,- Show your DTM/DSM in the view,- Select it, all informations about it (including resolution are displayed on the screen and in the log. Resolution is in meters.

Other ways are to send the DTM/DSM to a tabular view, or to export its attributes to a file (menu Export/3D Geometry/Attributes export (csv))